Furniture, automotive seat coverings and other upholstery applications have long employed hog rings, stitching or fasteners to secure the edges or seams of the upholstery or other fabric panels to an underlying structure, e.g., a seat or furniture frame.
Seats for cars and light trucks have been formed by molding a foam bun that serves as the seat cushion. A pre-stitched fabric cover is then attached to the foam bun. Often, the fabric cover is attached to the foam bun by insert molding touch fastener strips into the outer surface of the foam bun and attaching cooperating touch fastener products to an inner surface of the fabric cover. The mating portion of the separable fastener is attached to the seat cover to provide releasable attachment to the foam seat bun.
In some assemblies, a magnetically attractive material is attached to the fastener to temporarily hold the fastener in a trough or channel of the mold cavity wall, which is equipped with magnets. It is also possible to incorporate magnetically attractive material into the body of the fastener itself, such as in a plastic material that is used to make the fastener.
The touch fastener strips on the foam bun are typically recessed in trenches, to allow the seams in the fabric cover to be indented below the surface of the seat cushion. Indenting the seams in this manner forms aesthetically appealing indented creases in the surface of the seat cushion upholstery for a tailored look. The trenches also accommodate the additional thickness of upholstery fabric that is created where the seam is stitched.
The molded resin article is covered along its contour with a seat cover (i.e., upholstery material) by the engaging function between the engaging elements on the inner surface of the seat cover and the engaging elements of the fastener strip.
Generally, the fastener products are attached to the fabric cover along the seams where the cover is stitched together and held in place by the seam stitching. The touch fastener products allow the seat manufacturer to rapidly and semi-permanently attach the fabric cover to the foam bun by pulling the fabric cover over the foam bun and pressing the seam of the fabric cover down in to the foam bun trench to engage the cooperating touch fastener products on the foam bun and fabric.
FIG. 1 illustrates an example of a prior art seat covering installation 102 in which a fabric seam 104 between fabric panels 106, 108 is retained within a trench 110 in a seat foam bun 112 via a touch fastener strip 114 in trench 110 and a cooperative touch fastener material, e.g., loops 116 secured along an edge of seam 104. Some examples of the use of fastener strips to secure fabric panels to automotive seat foam buns are disclosed in U.S. Pat. Nos. 7,077,473 and 7,108,904.
Other prior art installations employ point attachment or clip systems, e.g., hog rings with attachment or anchor points approximately 100 mm apart. Such installations can be prone to creep, resulting in puckering or trim wrinkles near the attachment points. Such systems can also require a high force to engage the bead into the clip. Accordingly, improvements are sought in the efficacy and efficiency of attachment or anchoring of upholstery, fabrics and other panels or materials.